Head coach John Harbaugh said after Sunday's win over the Jaguars that Stanley is in the concussion protocol, Jeff Zrebiec of The Athletic reports.
Stanley missed time due to a knee injury earlier this season, but his status for Week 16 is up in the air due to a concussion. If he's unable to suit up next Monday against the 49ers, Patrick Mekari and Daniel Faalele would be candidates to see increased playing time.